A cooling-liquid circulation flow-channel through which a cooling-liquid flows in circulation is connected to a fuel cell. And, a radiator (heat-releasing unit) is disposed on the way of the cooling-liquid circulation flow-channel. In addition, a radiator bypass flow-channel is disposed, which connects the cooling-liquid circulation flow-channel on the upstream side of the radiator and the cooling-liquid circulation flow-channel on the downstream side of the radiator. Furthermore, a three-way valve is disposed at a junction between the cooling-liquid circulation flow-channel and the radiator bypass flow-channel. With the foregoing configuration, the flow-rate of the cooling-liquid flowing through the radiator and the flow-rate of the cooling-liquid bypassing the radiator are regulated by the three-way valve. As a result, the cooling-liquid is conditioned at an appropriate temperature, and the fuel cell is conditioned at an adequate temperature in accordance with the operational state thereof.
Meanwhile, too much cost is required when an electronic control valve is used for the three-way valve. Therefore, in JP2007-305519A, the temperature of the cooling-liquid is adjusted by using a thermostat valve and by controlling the rotation of a cooling-liquid pump.